Until recently, the production of pluripotent "multipurpose" stem cells from skin cells was considered to be the ultimate new development. In the meantime, it has become possible to directly convert cells of the body into one another -- without the time-consuming detour via a pluripotent intermediate stage. However, this method has so far been rather inefficient. Scientists from the Bonn Institute of Reconstructive Neurobiology (Director: Prof. Dr. Oliver Brüstle) have now developed the method to the point that it can be used for biomedical applications.